The model railroader has had various couplers available for use in coupling and uncoupling of model rail or freight cars. Of these, the most popular coupler has been a hook type coupler or a variation thereof. These couplers have been used with all types of railroad systems, the most popular models adapted for "HO" gauge or "N" gauge track.
In an attempt to provide remote control and authenticity, magnetic coupling and uncoupling systems were developed, as exemplified in U.S. Pat. No. 3,111,229 and U.S. Pat. No. 3,115,255. Delayed action magnetic couplers were introduced to overcome inadequateness of these prototypes, as shown in U.S. Pat. Nos. 3,117,676 and 3,469,713. In these later attempts, alterations of the housing pivot, shank and knuckle were made.
A difficulty with conventional magnetic couplers exists with the uncoupling pin which extends downward from the coupler, perpendicular to the track rail surface and the "between-the-track" arrangement of the magnetic field. If the downward extended pin comes too close to the surface of the rail, it oftentimes hits the side of the track, snags at switch points, frogs on rerailing ramps or even within its own uncoupling ramp, causing inadvertent uncoupling and derailments of the rolling stock. As a result of this basic problem, some model railroaders simply cut the pin from the coupler and then use hand uncoupling to effect separation or uncoupling of rolling stock when it is desired, which is far from being prototypical.
Another unsolved problem resides in the incompatibility of a magnetic coupler system with conventional hook-horn coupler design which is available on rolling stock, such as "HO" gauge in ready-to-run or kit form. These conventional couplers do not operate by delayed uncoupling, which is defined as the means whereby rolling stock can be uncoupled, spotted and released at any desired location on a model railroad layout from a single remote uncoupling site. If the model railroader wishes to convert a conventional hook-horn type coupler to a delayed uncoupling system, he must also replace the conventional couplers, possibly the coupler pocket housings, and in some cases the entire truck frame, which may include ferromagnetic wheels and/or axles. This is a time consuming disadvantage that also adds to the cost of rolling stock.